Writing on U.S. President Donald Trump's potential meeting with Kim Jong-un has been difficult because of the question of what to make of Trump's constant shifting and deliberate oscillation between on-again and off-again positions. Trump supporters call it strategic maneuvering as part of his "art of the deal" and critics call it his unstable element of danger in the art of diplomacy.Last week, Kim Yong-chol, Pyongyang's point man for the U.S., delivered a letter from Kim Jong-un to President Trump at the White House on June 1. The letter would be treated as a reply to Trump's May 24 letter that cancelled the June 12 summit, in which Trump asked the North Korean leader to "call him or write," if he had changed his mind. Trump's letter was never intended to be final. It was conditional, and it has appeared that the conditions were being mended through a flurry of meetings with the North Koreans. The neighboring countries around the peninsula including Japan, China and Russia are also busy trying to protect their interests regarding the Trump-Kim meeting. They don't want to be left out. As of now, Trump's summit is back on. Since Trump accepted the summit on March 8, there have been more positive, rather than negative, indications including Trump's eagerness in favor of holding a historic summit, as the world hopes it can avoid war and achieve denuclearization. A final announcement is yet to come from Trump himself within a matter of days. Even if the expected summit happens on schedule or even on a later date which is still possible, Trump knows that he will not be able to win everything he wants. He seems to be learning more about what is involved in making a nuclear deal with North Korea. He is now talking about the possibility of more than one meeting to denuclearize the North and he mentioned the physical necessity of a phased resolution.When all the preparations are completed at the working levels, the details of any possible agreement on a denuclearization path and its implementation, or how to guarantee the security and economic assistance to the North, will not be made public before the summit. U.S. Secretary of State Mike Pompeo said the North Koreans are still "contemplating" whether to make a strategic decision to give up their nuclear weapons in exchange for a brighter path of a normal state. Since Trump's cancellation of the summit, much has happened at a hectic pace. A conciliatory statement from the North, saying that their "anger and hostility" Trump had cited as a reason to cancel the summit was "only a reaction" to hawkish statements from Washington and they were open to resolve the issues at any time, in any format.South Korean President Moon and North Korean leader Kim Jong-un met for the second time at Panmunjeom in less than a month since they first met and agreed to work together for a successful U.S.-North Korea summit. Moon is even seeking a trilateral summit among the U.S and the two Koreas to declare an end to war in Korea, in reinforcement of a U.S. security assurance to North Korea.Also at Panmunjom, a U.S. team led by Sung Kim, U.S. ambassador to the Philippines and a former negotiator on the nuclear issue and a North Korean team headed by vice foreign minister Choi Son-hui, had held meetings on two separate days to discuss the agenda and a general path to denuclearization to prepare for their leaders' "expected" meeting. In Singapore, another set of summit preparation talks has been underway to arrange the logistical, protocol, and security details for the summit. The U.S. advance team is headed by White House deputy chief of staff Joe Hagin and the North Korean team by Kim Chang-sun, chief secretary to the Korean leader. This particular set of meetings is expected to proceed more cooperatively than the other meetings that tackle the substance of what will actually be discussed at the summit. While no satisfactory agreement on how to resolve the denuclearization issue seems to be in place, these discussions must have contributed to mutual understanding of what each side's demands are and what is acceptable or not acceptable by each side. As Trump says, we will see what happensTong Kim (tong.kim8@yahoo.com) is a Washington correspondent and columnist for The Korea Times. He is also a fellow at the Institute of Korean-American Studies.